Cytogenetic behaviour in octoploid Triticale

Meiosis and fertility in F1 hybrids between octoploid Triticale strains have been investigated. A reduction of the chiasma frequency was observed between diakinesis and first metaphase in F1 hybrids as well as in parents and other octoploid strains. Chiasma frequency at diakinesis was approximately the same in the F1 hybrids as in the parents, but at first metaphase chiasma frequency was considerably lower in the F1 hybrids than in the parents. There was a higher frequency of meiotic irregularities such as univalents, multivalents and micronuclei in F1 than in parents. As compared with the parents, fertility was lower in the F1 hybrids. Meiosis and fertility in the hybrids is discussed in relation to structural rearrangements and possible substitutions of chromosomes.